- #1
ppy
- 64
- 0
2 particles of charge q are placed at 2 vertices of an equilateral triangle of side a. An electric dipole is placed at the third vertex with its dipole moment orientated parallel to the opposite side of the triangle.
a) Determine the magnitude of the torque on the dipole due to the electric field from the 2 point charges?
b) Using F=-∇U where U=-p.E is the potential energy of a dipole moment p in an electric field E determine the magnitude and the direction of the translational force on the dipole due to the electric field from the 2 point charges.
c) Determine the magnitude of the electric field from the dipole at the position of one of the charges
This is what I have however I am very confused.
a) [itex]\tau[/itex]=pxE=pEsinθ
For 1 point charge E=q/4[itex]\pi[/itex]ε[itex]_{0}[/itex]a[itex]^{2}[/itex]
[itex]\tau[/itex]=2pqsin(45)/4[itex]\pi[/itex]ε[itex]_{0}[/itex]=[itex]\sqrt{2}[/itex]pq/4[itex]\pi[/itex]ε[itex]_{0}[/itex]
I thought the 2 is needed because you have the 2 point charges of charge q however I don't know can you just add them as it is a magnitude
c) I know that the electric field for a dipole is ([itex]\frac{2pcosθ}{4\piε_{0}}[/itex]r[itex]^{3}[/itex], [itex]\frac{psinθ}{4\piε_{0}}[/itex]r[itex]^{3}[/itex], 0) in spherical polars.
a) Determine the magnitude of the torque on the dipole due to the electric field from the 2 point charges?
b) Using F=-∇U where U=-p.E is the potential energy of a dipole moment p in an electric field E determine the magnitude and the direction of the translational force on the dipole due to the electric field from the 2 point charges.
c) Determine the magnitude of the electric field from the dipole at the position of one of the charges
This is what I have however I am very confused.
a) [itex]\tau[/itex]=pxE=pEsinθ
For 1 point charge E=q/4[itex]\pi[/itex]ε[itex]_{0}[/itex]a[itex]^{2}[/itex]
[itex]\tau[/itex]=2pqsin(45)/4[itex]\pi[/itex]ε[itex]_{0}[/itex]=[itex]\sqrt{2}[/itex]pq/4[itex]\pi[/itex]ε[itex]_{0}[/itex]
I thought the 2 is needed because you have the 2 point charges of charge q however I don't know can you just add them as it is a magnitude
c) I know that the electric field for a dipole is ([itex]\frac{2pcosθ}{4\piε_{0}}[/itex]r[itex]^{3}[/itex], [itex]\frac{psinθ}{4\piε_{0}}[/itex]r[itex]^{3}[/itex], 0) in spherical polars.